24 research outputs found

    Mechanical Impacts of Embedded Fibre Optics in 3D Printed Structures via Fused Deposition Modelling

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    This project explores the mechanical effects of embedded optical fibres in additively manufactured structures using the fused deposition modelling method. The aim is to develop a new and broad understanding of the effects these fibres have on the tensile and flexural properties of 3D printed polylactic acid. The bonding strength between the fibre and matrix material is also investigated by way of a fibre pull-out test. Micro-CT X-ray scanning is also used to visualise the internal structures of printed specimens and how different printing parameters; specifically infill pattern and infill density, impact the quality of the embedded fibre. Infill patterns cubic, grid and triangles were examined as plain samples without fibre at low, medium, high, and maximum density. Triangle infill was chosen to be the underlying infill pattern for samples containing fibre. A concentric infill was also selected to see behaviours when infill raster lines are coaxial to an embedded optical fibre. Manual fibre laying was found to be the most suitable method for producing fibre samples. Fibre sample variables were devised to investigate how different print settings may alter the quality of fibre embedding and mechanical properties. These included: adding extra material around the fibre, rotating the fibre, and altering the direction of raster lines over a central fibre. The type of buffer coating the optical fibre was also altered for micro-CT imaging and fibre pull-out testing. It was found that, in most cases, a single embedded optical fibre improves tensile and flexural mechanical properties

    Chevalier Jackson, M.D. (1865-1958): Il ne se repose jamais.

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    In the final year of the American Civil War, 1865, Chevalier Jackson was born on the 4th of November just outside Pittsburgh, Pennsylvania. The eldest of three sons of a poor, livestock-raising family, Jackson was raised in a period of social and political unrest. He was perhaps an even more unrestful boy. The description of his childhood days from his father’s father—Il ne se repose jamais, ‘‘He never rests’’—would ultimately reflect the man, doctor, and evangelist Jackson would later become.1 Indeed, he never did rest, Jackson would tirelessly pave the way for modern bronchoscopy and endoscopy as a whole; bringing international renown not only to himself, but also to his specialty

    Exertional rhabdomyolysis in a 21-year-old, healthy female after performing three sets of the biceps curl exercise to failure with 30% 1RM: A case report

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    Background: The optimal resistance training program to elicit muscle hypertrophy has been consistently debated and researched. Although 3 sets of 10 repetitions at 70-80% of the 1-repetition maximum (1RM) is widely recommended, recent studies have shown that low-load (~30% 1RM), high-repetition (3 sets of 30-40 repetitions) resistance training can elicit similar muscular hypertrophy. Therefore, this type of resistance training has gained popularity, perhaps because less weight is lifted for a longer duration. In the process of testing this hypothesis in a research study in our laboratory, a subject diagnosed with exertional rhabdomyolysis after completing a single resistance training session that involved 3 sets to failure at 30% 1RM. Exertional rhabdomyolysis is a condition characterized by the excessive breakdown of striated skeletal muscle that releases proteins from the muscle cell, particularly myoglobin, into the blood that can be toxic to the kidneys and is a significant health concern. Case Report: Reviewed were the events leading up to and throughout the diagnosis of exertional rhabdomyolysis in a healthy, recreationally-trained, 21-year-old female that was enrolled in a study that compared the acute effects of the traditional high-load, low-repetition versus low-load, high-repetition resistance training. The subject completed a total of 143 repetitions of the bilateral dumbbell bicep curl exercise. Three days post-exercise she reported excessive muscle soreness and swelling and sought medical attention. She was briefly hospitalized and then discharged with instructions to take acetaminophen for soreness, drink plenty of water, rest, and monitor her creatine kinase (CK) concentrations. Changes in the subject’s CK concentrations, ultrasound-determined muscle thickness and echo intensity were monitored over a 14-day period are reported. Discussion: This case illustrates the potential risk of developing exertional rhabdomyolysis after a low-load, high-repetition resistance training session in healthy, young, recreationally-trained women. The fact that exertional rhabdomyolysis is a possible outcome is enough to warrant caution when prescribing this type of resistance exercise

    Exertional rhabdomyolysis in a 21-year-old, healthy female after performing three sets of the biceps curl exercise to failure with 30% 1RM: A case report

    Get PDF
    Background: The optimal resistance training program to elicit muscle hypertrophy has been consistently debated and researched. Although 3 sets of 10 repetitions at 70-80% of the 1-repetition maximum (1RM) is widely recommended, recent studies have shown that low-load (~30% 1RM), high-repetition (3 sets of 30-40 repetitions) resistance training can elicit similar muscular hypertrophy. Therefore, this type of resistance training has gained popularity, perhaps because less weight is lifted for a longer duration. In the process of testing this hypothesis in a research study in our laboratory, a subject diagnosed with exertional rhabdomyolysis after completing a single resistance training session that involved 3 sets to failure at 30% 1RM. Exertional rhabdomyolysis is a condition characterized by the excessive breakdown of striated skeletal muscle that releases proteins from the muscle cell, particularly myoglobin, into the blood that can be toxic to the kidneys and is a significant health concern. Case Report: Reviewed were the events leading up to and throughout the diagnosis of exertional rhabdomyolysis in a healthy, recreationally-trained, 21-year-old female that was enrolled in a study that compared the acute effects of the traditional high-load, low-repetition versus low-load, high-repetition resistance training. The subject completed a total of 143 repetitions of the bilateral dumbbell bicep curl exercise. Three days post-exercise she reported excessive muscle soreness and swelling and sought medical attention. She was briefly hospitalized and then discharged with instructions to take acetaminophen for soreness, drink plenty of water, rest, and monitor her creatine kinase (CK) concentrations. Changes in the subject’s CK concentrations, ultrasound-determined muscle thickness and echo intensity were monitored over a 14-day period are reported. Discussion: This case illustrates the potential risk of developing exertional rhabdomyolysis after a low-load, high-repetition resistance training session in healthy, young, recreationally-trained women. The fact that exertional rhabdomyolysis is a possible outcome is enough to warrant caution when prescribing this type of resistance exercise

    Oncologic efficacy is not compromised, and may be improved with minimally invasive esophagectomy.

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    BACKGROUND: Major morbidity and mortality rates continue to be high in large series of transthoracic esophagectomies. Minimally invasive approaches are being increasingly used. We compare our growing series of minimally invasive (combined thoracoscopic and laparoscopic) esophagectomies (MIEs) with a series of open transthoracic esophagectomies. STUDY DESIGN: We identified 65 patients who underwent an MIE with thoracoscopy/laparotomy (n = 11), Ivor Lewis (n = 2), or 3-hole approach (n = 52). These patients were compared with 53 patients who underwent open Ivor-Lewis esophagectomy (n = 15) or 3-hole esophagectomy (n = 38) over the past 10 years. RESULTS: The MIE and open groups were similar regarding gender and average age. The majority of patients in the open group underwent neoadjuvant chemoradiation therapy (81%); a significantly smaller (43%) number of patients in the MIE group underwent neoadjuvant therapy (p \u3c 0.0001). Regarding oncologic efficacy, 97% and 94% of patients in both groups underwent R0 resections. Patients undergoing MIE had a significant increase in the number of harvested lymph nodes (median 20 vs 9; p \u3c 0.0001). Length of stay was significantly decreased in patients who underwent MIE (8.5 days vs 16 days; p = 0.002). Finally, there were significantly fewer serious complications (grades 3-5) in the MIE group (19% vs 48%; p = 0.0008). CONCLUSIONS: In this initial report of a single-institution series of MIE, we demonstrate that oncologic efficacy is not compromised and may actually be improved with a significantly increased number of harvested LNs. We also demonstrate that this approach is associated with fewer serious complications and a significant decrease in the length of postoperative hospital stay
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